The invention concerns a paper container for hot liquids. In particular, the container is of the type which comprises a wound jacket, a bottom set into the jacket and preferably recessed from the bottom edge of the container, together with a support surface for a tight cover, and deformation areas which permit a controlled reduction in container volume during the cooling of the liquid contained therein.
Paper containers to be filled with liquids generally are provided at least on the inside with a liquid-tight coating. In view of the winding process, the outer form is, in general, cylindrical or slightly conical. From EP-OS No. 68 334 a paper container of the afore-described type is known. Into such containers, liquids such as fruit juices or coffee, for example, are usually filled in a hot state. Hot filling is intended to preserve the contents without the use of chemicals.
Following the filling and sealing of such paper containers, reduced pressure is generated within the container during the cooling of the contents, which leads to an unattractive deformation of the container jacket. To remedy this situation, the paper container according to EP-OS No. 68 334 is provided along the generating lines of the jacket with linear creases, whereby the jacket is given a polygonal configuration in the center area. During the filling of a hot liquid, pressure rolls are applied to the polygonal surfaces, which subsequently are deformed during the cooling process in a controlled and uniform manner. A container is produced, the jacket thereof being cylindrical in the upper and lower area and polygonal in the center. It is a disadvantage that not only is an increased manufacturing effort necessary for the jacket itself, but that during the filling of th paper container, additional tools must be applied to the jacket.
It is an object of the invention to enable a novel paper container to be made in which the reduced pressure generated inside the container upon the cooling of the hot liquid will not lead to deformations that would alter or detrimentally affect the exposed outside of the container.